Rhyacian
| Rhyacian | ||||||||||||||||||||
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A sample of a Rhyacian banded iron formation found in North America | ||||||||||||||||||||
| Chronology | ||||||||||||||||||||
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| Etymology | ||||||||||||||||||||
| Name formality | Formal | |||||||||||||||||||
| Usage information | ||||||||||||||||||||
| Celestial body | Earth | |||||||||||||||||||
| Regional usage | Global (ICS) | |||||||||||||||||||
| Time scale(s) used | ICS Time Scale | |||||||||||||||||||
| Definition | ||||||||||||||||||||
| Chronological unit | Period | |||||||||||||||||||
| Stratigraphic unit | System | |||||||||||||||||||
| Time span formality | Formal | |||||||||||||||||||
| Lower boundary definition | Defined Chronometrically | |||||||||||||||||||
| Lower GSSA ratified | 1990[2] | |||||||||||||||||||
| Upper boundary definition | Defined Chronometrically | |||||||||||||||||||
| Upper GSSA ratified | 1990[2] | |||||||||||||||||||
The Rhyacian (/raɪˈeɪsiən/; from Ancient Greek ῥύαξ (rhúax) 'stream of lava') is the second geologic period in the Paleoproterozoic Era. It spans 250 million years and lasted from 2300 to 2050 million years ago (Ma), following the Siderian Period and preceding the Orosirian Period. Instead of being based on stratigraphy, these dates are defined chronometrically.
The Bushveld Igneous Complex and some other similar intrusions formed during this period.[3]
The Huronian (Makganyene) global glaciation began at the start of the Rhyacian and lasted 100 million years. It lasted about 80% of this period.[4]
For the time interval from 2250 Ma to 2060 Ma, an alternative period based on stratigraphy rather than chronometry, named either the Jatulian or the Eukaryian, was suggested in the geological timescale review 2012 edited by Gradstein et al.,[5] but as of December 2024, this has not yet been officially adopted by the IUGS.[6] The term Jatulian is, however, used in the regional stratigraphy of the Paleoproterozoic rocks of Fennoscandia.[7]
This is when the eukaryotes are thought to have originated from the symbiosis between asgardarchaea and alphaproteobacteria, as well as the sexual reproduction found within the eukaryotes only, thus the alternative name Eukaryian.[8][9][10] Macroscopic life is discovered to have started during the Rhyacian period.[11][12]
References
- ^ Teitler, Yoram; Hir, Guillaume Le; Fluteau, Frédéric; Philippot, Pascal; Donnadieu, Yannick (June 2014). "Investigating the Paleoproterozoic glaciations with 3-D climate modeling". Earth and Planetary Science Letters. 395: 71–80. Bibcode:2014E&PSL.395...71T. doi:10.1016/j.epsl.2014.03.044. eISSN 1385-013X. ISSN 0012-821X. LCCN 66009932. OCLC 1567193. Retrieved December 10, 2025.
- ^ a b Plumb, Kenneth A. (June 1991). "New Precambrian time scale". Episodes. 14 (2): 139–140. doi:10.18814/epiiugs/1991/v14i2/005. eISSN 2586-1298. ISSN 0705-3797. LCCN 78646808. OCLC 4130038.
- ^ James G. Ogg (2004). "Status on Divisions of the International Geologic Time Scale". Lethaia. 37 (2): 183–199. doi:10.1080/00241160410006492.
- ^ Kopp; Kirschvink, JL; Hilburn, IA; Nash, CZ; et al. (August 2005). "The Paleoproterozoic Snowball: A climate disaster triggered by the evolution of oxygenic photosynthesis" (PDF). PNAS. 102 (32): 11131–6. Bibcode:2005PNAS..10211131K. doi:10.1073/pnas.0504878102. PMC 1183582. PMID 16061801.
- ^ Gradstein, F.M.; et al., eds. (2012). The Geologic Time Scale 2012. Vol. 1. Elsevier. pp. 361–365. ISBN 978-0-44-459390-0.
- ^ "International Chronostratigraphic Chart". International Commission on Stratigraphy. December 2024. Retrieved 13 October 2025.
- ^ Bingen, B.; Solli, A.; Viola, G.; Torgersen, E.; Sandstad, J.S.; Whitehouse, M.J.; Røhr, T.S.; Ganerød, M.; Nasuti, A. (2015). "Geochronology of the Palaeoproterozoic Kautokeino Greenstone Belt, Finnmark, Norway: Tectonic implications in a Fennoscandia context" (PDF). Norwegian Journal of Geology. 95: 365–396. doi:10.17850/njg95-3-09.
- ^ Strassert, Jürgen F. H.; Irisarri, Iker; Williams, Tom A.; Burki, Fabien (2021). "A molecular timescale for eukaryote evolution with implications for the origin of red algal-derived plastids". Nature. 12 (1): 1879. Bibcode:2021NatCo..12.1879S. doi:10.1038/s41467-021-22044-z. PMC 7994803. PMID 33767194.
- ^ Mänd, Kaarel; Lalonde, Stefan V.; Robbins, Leslie J.; Thoby, Marie; Paiste, Kärt; Kreitsmann, Timmu; Paiste, Päärn; Reinhard, Christopher T.; Romashkin, Alexandr E.; Planavsky, Noah J.; Kirsimäe, Kalle; Lepland, Aivo; Konhauser, Kurt O. (April 2020). "Palaeoproterozoic oxygenated oceans following the Lomagundi–Jatuli Event". Nature Geoscience. 13 (4): 302–306. Bibcode:2020NatGe..13..302M. doi:10.1038/s41561-020-0558-5. hdl:10037/19269. S2CID 212732729.
- ^ Van Kranendonk, Martin J. (2012). "16: A Chronostratigraphic Division of the Precambrian: Possibilities and Challenges". In Felix M. Gradstein; James G. Ogg; Mark D. Schmitz; abi M. Ogg (eds.). The geologic time scale 2012 (1st ed.). Amsterdam: Elsevier. pp. 359–365. doi:10.1016/B978-0-444-59425-9.00016-0. ISBN 978-0-44-459425-9.
- ^ Chi Fru, Ernest; Aubineau, Jérémie; Bankole, Olabode; Ghnahalla, Mohamed; Tamehe, Landry Soh; El Albani, Abderrazak (August 2024). "Hydrothermal seawater eutrophication triggered local macrobiological experimentation in the 2100 Ma Paleoproterozoic Francevillian sub-basin". Precambrian Research. 409 107453. doi:10.1016/j.precamres.2024.107453.
- ^ https://phys.org/news/2024-07-complex-life-earth-began-billion.html
Further reading
- "Rhyacian Period". GeoWhen Database. Archived from the original on August 19, 2006. Retrieved January 5, 2006.